The Internet is evolving from a human-centered connection network through which humans create and consume information to an Internet of Things (IoT) network through which distributed elements, such as objects, exchange and process information. Internet of Everything (IoE) technology, which is a combination of IoT technology and big data processing technology through connection with a cloud server is also emerging. In order to implement the IoT, technology elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and thus technology for inter-object connection, such as a sensor network, machine to machine (M2M) communication, or machine type communication (MTC), has recently been studied.
In an IoT environment, intelligent Internet technology (IT) services that collect and analyze data generated by connected objects and create new value in human life may be provided. IoT may be applied to fields such as a smart home, a smart building, a smart city, a smart car or a connected car, a smart grid, health care, a smart home appliance, and an advanced medical service through convergence and integration of existing IT technology and various industries.
With advancements in communication technology and terminals, a push-to-talk (PTT) service in which a multi-party call may be made and hundreds of people may participate is being popularized.
A PTT service is a radio service in which a mobile phone may be used like a walkie-talkie and many people may simultaneously listen to a user speaking on the mobile phone with a single button press. That is, in a PTT service, simple communication may be performed as soon as a button is pressed and a relatively fast communication service may be provided when compared to a latency time of a general mobile phone.
Also, a PPT service may be used on-site as well as for remote conferencing. In particular, a voice call is used for fast communication in a high-risk workplace where many people are working or in an emergency situation such as a disaster situation.
However, when users' terminals are located within a short range during a multi-party call, a howling path may be formed between the terminals thus generating an amplified roaring sound, and thereby making it impossible to make a voice call.
Accordingly, there is demand for a method of suppressing or removing howling between terminals within a short range during a voice call.